MONACO -- Lewis Hamilton could feel the improvements made by Mercedes with its latest upgrade package, but said it was still clear where the car is lacking performance.
The Mercedes W14 features a new floor, upgraded front suspension and redesigned sidepods for this weekend as the team looks to address some of the issues that have held it back this year.
The updates were due to debut on the car last weekend at the Emilia Romagna Grand Prix, but the cancellation of that event meant they were on track for the first time in Monaco.
Hamilton finished the second practice session in sixth place, 0.498s off the pace of Max Verstappen, but praised the work on the car.
"I want to say a big, big thank you to everyone back in the factory, because to build and design and develop a car is not an easy thing, and everyone has put so much time in, so many hours of hard work to have us here today," Hamilton said.
"I'm glad we were able to keep it on-track for them, and I think we got a lot of data.
"It's not the place to ultimately test an upgrade, but the car was generally feeling good. It's a shame we weren't as close as I hoped at the end of the session. But definitely felt the improvements, and I'm grateful for that. Just got to keep chipping away at it and see if we can squeeze any more juice out of the car."
Asked if there were specific areas where the car had improved, he added: "There is, I'm not going to say where! But there is, and it's very clear where the lack is, lack of performance is for me.
"We'll talk about that in the debrief. We'll put our heads together, and try and figure out how we can do that within what we have. But hopefully this gives us a platform to build on moving forwards."
Hamilton doubts Mercedes will be able to challenge for pole position at Monaco on Saturday, but believes he will be able to improve on Friday's showing.
"In this session, we were close to half a second off I think, maybe that could have been three-tenths maybe," he said. "But I don't think we have half a second in the bag. We'll see. We'll work on it, and see if we can get some more out tonight."